Radio antenna



G. L. HALLER RADIO ANTENNA Maw 2, 195@ Filed Dec. 28, 1942 Patented May 2, 1950 anni UNITED STATES PATENT OFFICE RADIO ANTENNA George L. Haller, Dayton, Ghio Application December 28, 1942, Serial No. 470,377

12 Claims. (Cl. 25o-33) (Granted under the act f March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

My invention relates to an antenna which is useful over a wide range of Wave frequencies.

t is an object of my invention to provide such an antenna which is readily adjustable even by means controlled from a remote location,

A further object of my invention is to aord a device for matching the antenna and the transmission line thereto.

More specifically, I employ as an impedance matching device for the antenna and the transmission line, means providing inductance, for example, a shorted transmission line section.

Still another object of my invention is to iurnish an operating element for the antenna and the impedance matching device, which operating element has reversed threads connected so that the antenna and the impedance matching device are simultaneously lengthened or shortened.

For a further exposition of my invention reference may be had to the annexed drawing and specification at the end, whereof the novel features of my invention will be specifically pointed out and claimed.

In the drawings the single ligure is a view in perspective with parts in vertical cross section.

The embodiment of my invention selected from among others for illustration in the drawing and description in the specification comprises a metallic support I of hollow spool shape having at its upper end a horizontally extending flange 9 representing the ground plane and forming a counterpoise. Within the hollow center of support l is mounted an adjustable antenna 2 of which the portion extending above the flange 9 is the active radiating part. Mounted on flange 9 is a pocket 3 forming the connection for the concentric transmission line from which electrical connection is made to the slidable antenna 2 by means of contact Il which has wiping contact therewith.

The operating element of my device is a shaft 'l mounted in support I as by means of rotatable bearings and carrying at one end a gear 8 through which connection to any convenient operating device may be had.

Antenna 2 is driven from shaft 7 by means of insulating washer which has, at the rim of a hole at its center, metallic screw threads contacting the antenna and interengaging with `screw threads I0 on shaft 'I. Washer 5 is held against rotation by means of slot II and pin I2 riding therein.

In order to match the antenna to the transmission line, both the antenna and the transmission line must have the same value of impedance and, preferable, of resistance.. Most practical transmission lines have impedances of higher values than antennas particularly since the impedance at resonance is a substantially pure resistance. Therefore some means of matching the impedances of the antenna and of the transmission line must be employed. One method of matching is to reduce the length of the antenna to a value slightly less than that of the rst resonance point, at this length the antenna impedance at the base appears as a capacitive reactance in series with a resistance. To transform this impedance into a pure resistance of a desired higher value, an inductance of the correct value is shunted across the transmission line. The structure by means of which this is accomplished is a conducting disk 6 bearing at its outer rim in sliding electrical contact with support I and having, at the edge of an inner opening passing therethrough, screw threads interengagng with screw threads I3 on shaft 'I. Rotation of disk 6 with shaft I may be prevented by a loose coupling between them at their interengaging screw-threaded portions, or, if desired, a pin and slot arrangement similar to that associated with washer 5 may be provided. Screw threads I3 are reversed in direction to thread Ill so that washer 5 and disk B are moved in opposite directions whereby the efiective radiator portion of antenna 2 and the transmission line inductance are simultaneously shortened or lengthened. The movement of antenna 2 need not be at the same rate as that of disk 6 because threads I0 and I3 may have a diierent pitch.

Since many changes within the scope of my invention will be readily apparent to those skilled in the art, the claims set forth below are intended to be the only limitation I set.

I claim:

1. In a high frequencyradio receiver and trans- Vmitter, a metallic support having a hollow cylindrical portion, an antenna movably mounted in the hollow of said support and having a portion protruding outside said support, a metallic drive shaft rotatably mounted in the hollow of said support and having metallic engagement with said antenna, a stationary contact mounted on and insulated from said support and in electrical contact with said antenna and said drive shaft.

3 a metallic element providing a conductor between said drive shaft and said Vsupport and arranged so that said drive shaft and said conductor and said support form a short-circuited transmission line having an adjustable inductance, and screw-threads forming parts of said drive shaft and arranged to move said antenna and said conductor longitudinally of said support so that the radiating portion of said antenna and the effective length of said transmission line are substantially matched.

2. An antenna system comprising a radiating member, impedance matching means for said radiating member comprising a concentric line, the inner concentric conductor of said concentric line being rotatably mounted with respect to said outer concentric conductor and-electrically connected to said radiating member, shortcircuiting means spaced from the connection of said inner conductor to said radiating member and'electrically joining said inner and outer conductors, means associated With said radiating member and cooperating with said inner conductor to move said radiating member longitudinally with respect to said outer conductor in response to rotary rmovement of said inner conductor, and'means associated with said short circuiting means to move the same longitudinally with respect to said outer conductor in response to rotary.movement of said inner conductor.

3. VAn antenna system comprising an elongated antenna mast, impedance matching means for said antenna rnastcornprising a concentric line, said antenna mast being reciprocable into and from the outer conductor of said concentric line, the inner concentric conductor of said concentric line being rotatably mounted in said outer concentric conductor and electrically connected to vsaid antenna mast, an annular short 'circuiting disk spaced from the connection of said inner conductor to said antenna mast and electrically joining said innerand outerconductors, means connected'to said antenna mast and cooperatively engagingsaid inner conductor whereby to eect movenent of said antenna mast longitudinally .with respect to said outer conductor in response Y,to rotary movement of saidinner conductor, and

means on said short Vcircuiting disk cooperatively engaging said inner conductor to eiiect movement of said short circuiting disk longitudinally with respect to both said inner'and outer'conductors in response to rotary movement of said inner conductor.

Li. An antenna system comprising an elongated antenna mast, impedance matching rmeans for saidantenna mast comprising a concentric line, said antenna mast being reciprocable into and from the outer conductor of said concentric line, the inner concentric conductor of said concentric line being rotatably mounted in said outer Vconcentric conductor and in screw threaded engagement With said antenna mast adjacent the inner end thereof, said antenna mast and said inner conductor being electrically connected, and an Aannular short circuiting disk in screw threaded engagement with said inner 'conductor inspaced relation from 'the connection between said-inner Vconductor and said antenna mast, said 'short circuiting disk electrically Vjoining said inner and outer conductors, said inner conductor being adapted upon rotation to effect movement of both said antenna mast and said short circuiting disk longitudinally relative to said outer conductor, whereby to simultaneously adjust both lthe effective radiating'portion of said antenna 'l 4 mast and the eiective inductance of said matching means.

5. In combination, an antenna having an effective radiating portion, impedance matching means comprising a concentric line in electrical circuit with said antenna, the inner concentric conductor of said concentric line being rotatably mounted relative to the outer concentric conductor, means for adjusting the effective radiating portion oi said antenna in response to rotation of thel inner conductor, and short circuiting vmeans electrically joining the inner and outer conductors, said short circuiting means operable upon rotation of the inner conductor to move longitudinally relative to at least one of said concentric conductors, whereby to vary the ef- Yfective inductance of said matching means.

`c. Incombination, 'an antenna having an effective radiating portion, impedance matching means comprising a concentric line in electrical circuity with said antenna'the inner concentric conductor oi said concentric `line being'rotatably mounted relative to theputer concentric conductor, means for adjusting thel eiective radiating portion of said antenna inl response to rotary movement 'of kthe inner conductor, and means for varying the effective inductance of said matchingmeans in response to rotary movement of saidu inner conductor.

"7. uIn combination; an elongated antenna mast, an outer concentric conductor' -into and from which said antenna mast is reciprocable, an inner concentric conductor rotatably `Ymounted Within Asaidouter conductorand aligned with said antenna-mast, said outer and' inner conductors forming a ltunable impedance matching means for said antenna mast, means `for radjusting the eiective radiating portion of said antenna mast in response to rotary movement of the inner conductor, andmeans forvarying the eiective inductance of said matching means in response to rotary movement of said-inner conductor.

8. In combination, an antenna having an effective-radiating portion, impedance matching means'for said antennav comprising a pair of parallel'conductors `in electrical circuit With said antenna, a iirst one of said conductors being rotatably mounted relative to 'the second conductor,-ineans for'radjusting the 'effective radiating portion of 'said'- antenna -in response to rotationof the ifirst conductonvand short circuiting means v"electrically--joining the first and second jconductrirs,l said short circuiting means beingoper'able upon rotation or" the rst Conductor to move longitudinally relativeto at least one of said conductors, lwhereby to -varythe .effective in- -ductance of said matchingV means.

'9."In combination, an antenna having anei- :iective radiating (portion, impedance matching means for. said t antenna vcomprising a pair of parallel conductors in electrical circuit with said antenna, `said conductors being 4mounted `for relative rotary movement with respect to each other, means for adjusting the effective radiating Vportion of said antenna in response to relative rotary rmovementof said-conductors, and means for varying .the effective induc'zta'nce` of said match'ing means in response to relative rotary vvith respecttosaid outerconcentric conductor and electrically'connected to said radiating meinber, short circuiting means spaced from the connection of said inner conducto-r to said radiating member and electrically joining said inner and outer conductors, means associated with said radi ating member and cooperating with said inner conductor to move said radiating member longitudinally with respect to said outer conductor in response to rotary movement of said inner conductor, and means associated with said short crcuiting means to move the same longitudinally in the opposite direction to the movement of said radiating member with respect to said outer conductor in response to rotary movement of said inner conductor.

1l. An antenna system comprising an elongated antenneJ mast, an outer concentric conductor into and from which said antenna mast is reciprocable, an inner concentric conductor rotatably mounted in said outer concentric conductor and electrically connected to said antenna mast, an annular short circuiting disk spaced from the connection of said inner conductor to said antenna mast and electrically joining said inner and outer conductors, means connected to said antenna mast and cooperatively engaging said inner conductor whereby to effect movement of said antenna mast longitudinally with respect to said outer conductor in response to rotary movement of said inner conductor, and means on said short circuiting disk cooperatively engaging said inner conductor to effect movement of said short circuiting disk longitudinally with respect to both said inner and outer conductors in response to rotary movement of said inner conductor, said antenna mast and said short circuiting disk each being cooperatively associated with said inner conductor whereby to move in opposite directions upon rotation of said inner conductor.

12. An antenna system comprising an elongated antenna mast, an outer concentric conductor into and from which said antenna mast is reciprocable, an inner concentric conductor rotatably mounted in said outer concentric conductor and in screw threaded engagement with said antenna mast adjacent the inner end thereof, said antenna mast and said inner conductor being electrically connected, and an annular short circuiting disk in screw threaded engagement with said inner conductor in spaced relation from the connection between said inner conductor and said antenna mast, said short circuiting disk electrically joining said inner and outer conductors, said inner conductor being` adapted upon rotation to effect movement of both said antenna mast and said short circuiting disk longitudinally relative to said outer conductor, said screw threaded engagements being arranged such that said antenna mast and said short circuiting disk move in opposite directions along said inner conductor upon rotation of said inner conductor.

GEORGE L. HALLER.

REFERENCES CITED The following references are of record in the le of this partent:

UNITED STATES PATENTS Number Name Date 2,069,513 WoliT Feb. 2, 1937 2,168,860 Berndt Aug. 8, 1939 2,239,909 Buschbeck et al Apr. 29, 1941 2,275,342 Brown Mar. 3, 1942 2,278,531 Buschbeck Apr. 7, 1942 2,368,298 Harris Jan. 310, 1945 

